/***************************************************************************

  video.c

  Functions to emulate the video hardware of the machine.

***************************************************************************/

#include "driver.h"
#include "video/resnet.h"
#include "includes/phoenix.h"

UINT8 *naughtyb_videoram2;

/* use these to draw charset B */
UINT8 *naughtyb_scrollreg;

/* use this to select palette */
static UINT8 palreg;

/* used in Naughty Boy to select video bank */
static int bankreg;

// true if cabinet == cocktail -AND- handling player 2
int naughtyb_cocktail;

static const rectangle scrollvisiblearea =
{
	2*8, 34*8-1,
	0*8, 28*8-1
};

static const rectangle leftvisiblearea =
{
	0*8, 2*8-1,
	0*8, 28*8-1
};

static const rectangle rightvisiblearea =
{
	34*8, 36*8-1,
	0*8, 28*8-1
};

static const res_net_decode_info naughtyb_decode_info =
{
	2,		/*  two proms          */
	0,		/*  start at 0         */
	255,	/*  end at 255         */
	/*  R,   G,   B,   R,   G,   B */
	{   0,   0,   0, 256, 256, 256},		/*  offsets */
	{   0,   2,   1,  -1,   1,   0},		/*  shifts */
	{0x01,0x01,0x01,0x02,0x02,0x02}		    /*  masks */
};

static const res_net_info naughtyb_net_info =
{
	RES_NET_VCC_5V | RES_NET_VBIAS_5V | RES_NET_VIN_OPEN_COL,
	{
		{ RES_NET_AMP_NONE, 130, 270, 2, { 270, 1 } }, /* no resistor for bit1 */
		{ RES_NET_AMP_NONE, 130, 270, 2, { 270, 1 } }, /* no resistor for bit1 */
		{ RES_NET_AMP_NONE, 130, 270, 2, { 270, 1 } }  /* no resistor for bit1 */
	}
};

/***************************************************************************

  Convert the color PROMs into a more useable format.

  Naughty Boy has two 256x4 palette PROMs, one containing the high bits and
  the other the low bits (2x2x2 color space).
  The palette PROMs are connected to a 7407 (hex open collector buffer),
  which in turn is connected to the RGB output this way:

  bit 3 --
        -- 270 ohm resistor  -- GREEN
        -- 270 ohm resistor  -- BLUE
  bit 0 -- 270 ohm resistor  -- RED

  bit 3 --
        -- GREEN
        -- BLUE
  bit 0 -- RED

  plus 130 ohm pullup and 270 ohm pulldown resistors on all lines

***************************************************************************/

PALETTE_INIT( naughtyb )
{
	rgb_t	*rgb;
	int i;

	rgb = compute_res_net_all(color_prom, &naughtyb_decode_info, &naughtyb_net_info);
	for (i = 0; i < 0x100; i++)
		palette_set_color(machine, BITSWAP8(i,5,7,6,2,1,0,4,3), rgb[i]);
	free(rgb);

	palette_normalize_range(machine->palette, 0, 255, 0, 255);
}


/***************************************************************************

  Start the video hardware emulation.

***************************************************************************/
VIDEO_START( naughtyb )
{
	palreg = bankreg = 0;

	/* Naughty Boy has a virtual screen twice as large as the visible screen */
	machine->generic.tmpbitmap = auto_bitmap_alloc(machine,68*8,28*8,video_screen_get_format(machine->primary_screen));
}




WRITE8_HANDLER( naughtyb_videoreg_w )
{
	// bits 4+5 control the sound circuit
	pleiads_sound_control_c_w(space,offset,data);

	naughtyb_cocktail =
		( ( input_port_read(space->machine, "DSW0") & 0x80 ) &&	// cabinet == cocktail
		  ( data & 0x01 ) );				// handling player 2
	palreg  = (data >> 1) & 0x03;			// pallette sel is bit 1 & 2
	bankreg = (data >> 2) & 0x01;			// banksel is just bit 2
}

WRITE8_HANDLER( popflame_videoreg_w )
{
	// bits 4+5 control the sound circuit
	pleiads_sound_control_c_w(space,offset,data);

	naughtyb_cocktail =
		( ( input_port_read(space->machine, "DSW0") & 0x80 ) &&	// cabinet == cocktail
		  ( data & 0x01 ) );				// handling player 2
	palreg  = (data >> 1) & 0x03;			// pallette sel is bit 1 & 2
	bankreg = (data >> 3) & 0x01;			// banksel is just bit 3
}



/***************************************************************************

  The Naughty Boy screen is split into two sections by the hardware

  NonScrolled = 28x4 - (rows 0,1,34,35, as shown below)
  this area is split between the top and bottom of the screen,
  and the address mapping is really funky.

  Scrolled = 28x64, with a 28x32 viewport, as shown below
  Each column in the virtual screen is 64 (40h) characters high.
  Thus, column 27 is stored in VRAm at address 0-3fh,
  column 26 is stored at 40-7f, and so on.
  This illustration shows the horizonal scroll register set to zero,
  so the topmost 32 rows of the virtual screen are shown.

  The following screen-to-memory mapping. This is shown from player's viewpoint,
  which with the CRT rotated 90 degrees CCW. This example shows the horizonal
  scroll register set to zero.


                          COLUMN
                0   1   2    -    25  26  27
              -------------------------------
            0| 76E 76A 762   -   70A 706 702 |
             |                               |  Nonscrolled display
            1| 76F 76B 762   -   70B 707 703 |
             |-------------------------------| -----
            2| 6C0 680 640   -    80  40  00 |
             |                               |
        R   3| 6C1 681 641   -    81  41  01 |
        O    |                               |  28 x 32 viewport
        W   ||      |                 |      |  into 28x64 virtual,
             |                               |  scrollable screen
           32| 6DE 69E 65E        9E  5E  1E |
             |                               |
           33| 6DF 69F 65F   -    9F  5F  1F |
             |-------------------------------| -----
           34| 76C 768 764       708 704 700 |
             |                               |  Nonscrolled display
           35| 76D 769 765       709 705 701 |
              -------------------------------


***************************************************************************/
VIDEO_UPDATE( naughtyb )
{
	int offs;

	// for every character in the Video RAM

	for (offs = screen->machine->generic.videoram_size - 1;offs >= 0;offs--)
	{
		int sx,sy;

		if ( naughtyb_cocktail )
		{
			if (offs < 0x700)
			{
				sx = 63 - offs % 64;
				sy = 27 - offs / 64;
			}
			else
			{
				sx = 64 + ( 3 - (offs - 0x700) % 4 );
				sy = 27 - (offs - 0x700) / 4;
			}
		}
		else
		{
			if (offs < 0x700)
			{
				sx = offs % 64;
				sy = offs / 64;
			}
			else
			{
				sx = 64 + (offs - 0x700) % 4;
				sy = (offs - 0x700) / 4;
			}
		}

		drawgfx_opaque(screen->machine->generic.tmpbitmap,0,screen->machine->gfx[0],
				naughtyb_videoram2[offs] + 256 * bankreg,
				(naughtyb_videoram2[offs] >> 5) + 8 * palreg,
				naughtyb_cocktail,naughtyb_cocktail,
				8*sx,8*sy);

		drawgfx_transpen(screen->machine->generic.tmpbitmap,0,screen->machine->gfx[1],
				screen->machine->generic.videoram.u8[offs] + 256*bankreg,
				(screen->machine->generic.videoram.u8[offs] >> 5) + 8 * palreg,
				naughtyb_cocktail,naughtyb_cocktail,
				8*sx,8*sy,0);
	}

	// copy the temporary bitmap to the screen
	{
		int scrollx;

		copybitmap(bitmap,screen->machine->generic.tmpbitmap,0,0,-66*8,0,&leftvisiblearea);
		copybitmap(bitmap,screen->machine->generic.tmpbitmap,0,0,-30*8,0,&rightvisiblearea);

		scrollx = ( naughtyb_cocktail ) ? *naughtyb_scrollreg - 239 : -*naughtyb_scrollreg + 16;
		copyscrollbitmap(bitmap,screen->machine->generic.tmpbitmap,1,&scrollx,0,0,&scrollvisiblearea);
	}
	return 0;
}
